Recent progress in microelectronics has greatly miniaturized radio communication devices such as receivers, transmitters and antennas. This miniaturization has permitted the integration of these components into wrist-carried radio devices.
Such a portable wrist radiotelephone device is disclosed in U.S. Pat. No. 5,239,521 issued Aug. 24, 1993 to Blonder. The disclosed wrist radiotelephone device comprises a case having a display, and a strap having a top layer and a bottom layer. The top layer includes a releasable end which allows the top layer to separate from the bottom layer in the area where one end of the strap is attached to the case. The top layer of the strap remains attached to the bottom layer via a hinge which also permits the top layer to rotate. Embedded within the strap are a microphone and a speaker which are connected via conductors to a transceiver located in the case. The speaker is located at the releasable end of the top layer of the strap, and the microphone is located at the attached end of the top layer of the strap.
In operation, the released top layer is rotated in such a way that the speaker is located in the palm of the user's hand and the microphone is located along the inside of the user's forearm. The user's arm is raised so that the user's hand is cupped over the user's ear. Sound ports are located on a front side of the speaker facing the user's ear. The user's hand is oriented such that the user's palm containing the speaker is proximate to the user's ear and the microphone is proximate to the user's mouth. This arrangement allows for the device to be used as a telephone.